Apparatus and method for shaping a cylindrical metal tubular component

ABSTRACT

An apparatus and method for shaping an end of a cylindrical metal tubular component into a shaped mouth piece. A heated die is provided whose inner surface corresponds to the outer surface of the mouth piece to be produced, with means to progressively force said end into said die. In front of the die is provided a block having a duct for maintaining the tubular component in position during the forcing operation, cooling means surrounding said block to avoid a rise in temperature of the part of the component not in the course of being shaped.

United States Patent Creuzet Aug. 28, 1973 [54] APPARATUS AND METHOD FORSHAPING 1,983,584 12/1934 Urschel.... 72/342 X A CYLINDRICAL METALTUBULAR 3,600,927 8/1971 Wahler 72/353 COMPONENT FOREIGN PATENTS ORAPPLICATIONS [76] Invent: de Beyssac' ll9,678 3/1945 Australia 72/353Mamande 761,143 11/1956 Great Britain 22 i Jan. 20 1971 203,335 5/1959Germany 72/352 619,330 3/1949 Great Britain 21 Appl. No.2 107,893

Primary Examiner-Richard J. Herbst [30 'ror'ei n iicaiasmarinas, Mme/m5mm! Jan. 22, 1970 firsncelnffl ..f70022 5 [57] ABSTRACT 7 An apparatusand method for shaping an end of a cylini 72/342 Z drical metal tubularcomponent into a shaped mouth [58] i s 284 286 piece. A heated die isprovided whose inner surface 72,291 5 corresponds to the outer surfaceof the mouth piece to g be produced, with means to progressively forcesaid end into said die. In front of the die is provided a block having aduct for maintaining the tubular component in [56] References Citedposition during the forcing operation, coohng means UNITED STATESPATENTS surrounding said block to avoid a rise in temperature 1,891,33812/1932 Snell 72/286 X of the part of the component not in the course ofbeing v shaped 2,705,275 3/1955 Westin et 72/342 X 3 Claims, 9 DrawingFigures 2 5 1 2 26 I I T Patented Aug- 28,1973 3,754,429

2 Sheets-Sheet l \NVENTOR R0 BERT C a: U2. ET

y Wm R APPARATUS AND METHOD FOR SHAPING A CYLINDRICAL METAL TUBULARCOMPONENT FIELD OF THE INVENTION The invention relates to the shaping oftubular metal components.

In aeronauticaul construction and associated techniques it is desirableto have available, both as structural elements or as transmissionmembers, tubular components with ends whose diameter is less than thatof the body, the connecting parts being usually frustoconical. The endsserve for the connecting of the component, particularly by screwing.

PRIOR ART A method is known according to which the cylindrical componentis treated by two jaws with a frustoconical chucking range gripping thecomponent and shaping it by a succession of squeezing operations, thecomponent being progressively introduced between the two jaws which aremoved so as to alternately withdraw from one another and then approachone another.

With this method there is a' limit to the extent to which thecomponent's shape can be changed. Defects in the component are difficultto avoid. his often necessary to carry out an additional treatmentinvolving machining and/or annealing. The cost is rather high.

It has also been proposed, particularly for the manufacture of gascylinders, to upset a tubular component in a die with a shaping cavity.In many cases difficulties arise in this connection, particularlybecause of parasitic deformations, such as bends which occur.

The use of a plunger piston involves a considerable complication withouthowever giving completely satisfactory results.

SUMMARY OF THE INVENTION The invention relates to an apparatus forshaping an end of a cylindrical tubular metal component into a reducedmouth piece, comprising a heated die whose inner surface corresponds tothe outer surface of the mouth piece to be produced and means forprogressively forcing the said end into the die, the die being precededby a block providing a duct for maintaining the tubular component inposition during the forcing operation, means for cooling surrounding thesaid block designed to avoid a rise in temperature of the part of thetubular component not in the course of being shaped, which would affectits mechanical strength.

The invention likewise relates to a method for shaping the end of atubular component into a reduced mouth piece by forcing said end into ahot-wall shaping cavity, the tubular component being simultaneouslycooled and held in position by its contact with the cold By continuingthe thrust after the face of the component has abutted against aboundary surface of the cavity, a thickening of the frustoconical wallis obtained.

In one embodiment, in a final stage, the thrust on the component iscontinued and the progression of the end is efi'ected through acylindrical passage extending the frustoconical cavity, the end of whichis unobturated. In this way a jointing appendix is obtained withoutinterrupting the process.

The method according to the invention is applicable to components of avery wide range of metallic materials light alloys, steel, and so on,particularly for the production of connecting rods.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view inlongitudinal section of part of an apparatus in accordance with theinvention FIG. 2 is a view on a smaller scale, with the tube indifferent condition during treatment FIGS. 3 to 6 are views similar toFIG. 2, but for other conditions of the tube FIG. 7 relates to anapparatus according to the invention, but for a modification FIG. 8 issimilar to FIG. 7, for another condition of the tube FIG. 9 shows a tubeafter treatment, in longitudinal section.

The apparatus or device in accordance with the invention comprises aguide device 10 consisting of a block 11 having a cylindrical duct 12.The guide device 10 is followed by a die 13 having a cylindrical duct14, extending the duct 12 the cylindrical surface 14 extends by afrustoconical surface 15 the inner frustoconical surface 15 extends by acylindrical surface 16 which opens on to the front discharge surface 17.

In the cylindrical duct 16 may be removably introduced the body 21 of aplug 22, whose frontinner face 23, which is flat, lies in the plane ofthe circle 24 connecting the cylindrical surface 16 and thefrustoconical surface 15.

The block 11 is surrounded by a cooling device 25, for instance a coiledpipe with water circulation. The block forming the die 13 is surroundedby a heating device 26, preferably with electrical resistances.

The cylindrical tube 30 of light alloy for instance, such as that knownas AU2GN, or that known as AU4G1 whose end 31 is to be shaped, is firstof all preferably submitted, if requisite, to a cold-hardening andtrueing treatment, making it possible to obtain, on the one hand thediametrical and thickness dimensions required and on the other hand afine crystallization.

After lubricating its outer surface the tube is introduced by its end 31into the guide device 10, the diameter of the inner surface 12 beingsubstantially equal to that of the outer surface 32 of the tube, and itis introduced into the die 13 until its surface 33 comes into the plane34 connecting the cylindrical surface 14 and the frustoconical surface15. The progression movement of the tube is effected under the action ofa hydraulic press (not shown). The tube, heated by the device 26,gradually penetrates the frustoconical cavity 35, its outer surface 32abutting the inner surface 15, which is frustoconical (FIG. 2). As thetubular wall 36 penetrates the cavity 35, it increases in thickness inpropor-' the face 33 of the tube 30 comes into contact with the frontface or end 23 (FIG. 3), the thickness of the tube at the said face isgreater than the thickness of the original cylindrical wall thefrustoconical part of the tube thus shaped is defined by an outerfrustoconical surface 37, the taper of which is the same as that of thesurface 15, and an inner surface 38 with a more accentuated taper.

The invention also provides for continuing the thrust action, Duringthis stage the tube assembly no longer moves forward, but an increase inthickness is produced of the frustoconical wall 39 obtained during thepreceding stage, at the expense of the part 41, remaining cylindrical,of the tube end adjacent to the part 39 (FIG. 4). The operation iscontinued until the desired inner profile 42 is obtained, which ischosen in particular according to the final thickness desired for thecylindrical appendix.

The plug 21 is then removed, either by hand or automatically. Forinstance, the removal could be effected when the pressure of theapplication of the surface 33 against the end 23 exceeds a predeterminedvalue, or else after the lapse of a given period of time. The tubularcomponent assembly resumes its forward movement and a cylindrical end 44(FIG. is formed, the outer surface of which has the same diameter as theinner cylindrical surface 16, the thickness being substantially that ofthe portion 43. The thrust is interrupted when a cylindrical appendix 44of the desired length has been obtained, which length may besubstantially that of the cylindrical duct 16 (FIG. 6).

The finished component thus comprises, starting with a cylindrical body46 which has the same thickness as the original tube 30, a frustoconicalpart 47 whose thickness increases from the connecting part to the body46, and a cylindrical part 48, or end, the thickness of which is equalto the greatest thickness of the frustoconical part 47 of the wall.

It is possible to obtain by means of this method a frustoconical tubularpart whose internal diameter, having a straight section, is a smallfraction of the diameter of the large section, to the point of evenbeing closed, and without any defects appearing in the texture of themetal and/or the condition of the surface.

The inner surface 49 of the cylindrical end 48 may subsequently betapped for connecting the component to another similar or differentcomponent.

The other extremity of the component 30 may be treated in the samemanner to obtain the second finished end.

The invention provides a method of production in accordance with whichthe thread of the inner surface of the cylindrical end 48 is obtained inthe last stage of the thrust. In this mode of production, the die has acentral core 51 (FIG. 7). This core may, for instance, be introducedafter the removal of the plug 21. The outer surface of the said core hasa screwthread 52. During the thrust the frustoconical tubular part 53travels in the space provided between the core 51 and the inner surface16 (FIG. 8). The cylindrical end 54 is progressively formed and, duringthis movement, the core 51 is also entrained. When a sufficient lengthhas been attained, the removal of the core 5], simply by unscrewing,leaves a finished end 55 provided with its tapped thread 56 (FIG. 9). I

I claim:

1. A shaping device for shaping an end portion of a cylindrical tubemade of sheet metal, said device comprising:

a generally tubular guide block and an elongate ho]- low die memberdisposed in abutting and aligned relationship, said guide blockconstituting the feed end and the end of the die member opposite to theguide block the finishing end of the device, said guide block and saiddie member defining therein contiguous from the feed end toward thefinishing end of the device a first guide portion having an innerdiameter fitting the outer diameter of a tube to be shaped, acylindrical guide portion also having an inner diameter fitting theouter diameter of the tube, a frustoconical first shaping portiontapered toward said finishing end, said shaping portion having at itswide end an inner diameter equal to the inner diameter of the secondguide portion, and a cylindrical second shaping portion having an innerdiameter equal to the inner diameter of the first shaping portion at thenarrow end thereof, cooling means jacketing said guide block for coolinga tube portion therein, and heating means jacketing the second guideportion, the first shaping portion and the second shaping portion forheating said second guide portion'and the shaping portions to atemperature causing softening of a tube portion therein whereby uponforcing the tube to be shaped into the device from the feed end thereoftoward the finishing end the tube end portion when successively enteringthe first shaping portion and then the second shaping portion isdeformed to obtain a frusto-conical configuration and a cylindricalconfiguration of reduced diameter respectively, and the wall thicknessof the tube wall at the deformed end portion of the tube is increased soas to compensate for the decrease of the peripheral outline of the tubeat the deformed end portion thereof.

2. The shaping device according to claim 1 and comprising a plugincluding a cylindrical portion having an outer diameter fitting theinner diameter of said second shaping portion, said cylindrical plugportion being fit- 7 table into said second shaping portion of the diemember from the finishing end thereof.

3. The shaping device according to claim I and comprising an externallythreaded core member fittable into said second shaping portion from thefinishing end of the die member for internally threading a cylindricaltube portion of reduced diameter therein.

* i t i i

1. A shaping device for shaping an end portion of a cylindrical tubemade of sheet metal, said device comprising: a generally tubular guideblock and an elongate hollow die member disposed in abutting and alignedrelationship, said guide block constituting the feed end and the end ofthe die member opposite to the guide block the finishing end of thedevice, said guide block and said die member defining therein contiguousfrom the feed end toward the finishing end of the device a first guideportion having an inner diameter fitting the outer diameter of a tube tobe shaped, a cylindrical guide portion also having an inner diameterfitting the outer diameter of the tube, a frustoconical first shapingportion tapered toward said finishing end, said shaping portion havingat its wide end an inner diameter equal to the inner diameter of thesecond guide portion, and a cylindrical second shaping portion having aninner diameter equal to the inner diameter of the first shaping portionat the narrow end thereof, Cooling means jacketing said guide block forcooling a tube portion therein, and heating means jacketing the secondguide portion, the first shaping portion and the second shaping portionfor heating said second guide portion and the shaping portions to atemperature causing softening of a tube portion therein whereby uponforcing the tube to be shaped into the device from the feed end thereoftoward the finishing end the tube end portion when successively enteringthe first shaping portion and then the second shaping portion isdeformed to obtain a frustoconical configuration and a cylindricalconfiguration of reduced diameter respectively, and the wall thicknessof the tube wall at the deformed end portion of the tube is increased soas to compensate for the decrease of the peripheral outline of the tubeat the deformed end portion thereof.
 2. The shaping device according toclaim 1 and comprising a plug including a cylindrical portion having anouter diameter fitting the inner diameter of said second shapingportion, said cylindrical plug portion being fittable into said secondshaping portion of the die member from the finishing end thereof.
 3. Theshaping device according to claim 1 and comprising an externallythreaded core member fittable into said second shaping portion from thefinishing end of the die member for internally threading a cylindricaltube portion of reduced diameter therein.